PubMed Health⌕ Search

Biomedical subjects

C Marcassa

Publications and source records attributed to C Marcassa.

At least 19 recordsLinked to original sources
PubMed2006

The regulatory background of nuclear cardiology in Europe: a survey by the European Council of Nuclear Cardiology.

PURPOSE: Nuclear cardiology is a well-validated, non-invasive imaging modality that is highly cost-effective as a diagnostic and prognostic tool in the evaluation of patients with known or suspected coronary artery disease. However, the number of procedures in Europe is very far from that which would be expected on the basis of epidemiological data, particularly when comparison is made with the USA. As a preliminary step for future action aimed at improving and increasing nuclear cardiology practice in Europe, the European Council of Nuclear Cardiology performed a survey to identify the regulatory issues and the training components pertaining to the practice of nuclear cardiology. METHODS: a questionnaire was sent to 31 national nuclear medicine societies and to 40 national cardiology societies. The main areas covered by the survey were: (1) the license requirements, (2) the theoretical and practical aspects of training and (3) supervision of the stress test during a nuclear cardiology study. RESULTS: The results show that, in a setting of wide heterogeneity of national regulations, education and professional practice, nuclear medicine is a restricted and closely regulated specialty. This situation guarantees the quality and safe use of radionuclides; at the same time, however, it limits integration of nuclear medicine into the clinical arena. CONCLUSION: Cardiologists should become more involved in nuclear cardiology, to further stimulate the use of this powerful diagnostic and prognostic imaging modality.

Cardiology↗
PubMed2005

EANM/ESC procedural guidelines for myocardial perfusion imaging in nuclear cardiology.

The European procedural guidelines for radionuclide imaging of myocardial perfusion and viability are presented in 13 sections covering patient information, radiopharmaceuticals, injected activities and dosimetry, stress tests, imaging protocols and acquisition, quality control and reconstruction methods, gated studies and attenuation-scatter compensation, data analysis, reports and image display, and positron emission tomography. If the specific recommendations given could not be based on evidence from original, scientific studies, we tried to express this state-of-art. The guidelines are designed to assist in the practice of performing, interpreting and reporting myocardial perfusion SPET. The guidelines do not discuss clinical indications, benefits or drawbacks of radionuclide myocardial imaging compared to non-nuclear techniques, nor do they cover cost benefit or cost effectiveness.

Cardiology↗
PubMed2000

Independent and incremental prognostic value of (201)Tl lung uptake at rest in patients with severe postischemic left ventricular dysfunction.

BACKGROUND: An elevated (201)Tl lung uptake after stress is related to an adverse prognosis. METHODS AND RESULTS: The functional and prognostic significance of resting (201)Tl lung uptake was assessed in 124 consecutive patients with ischemic heart disease and ejection fraction </=35% undergoing rest-redistribution tomography to evaluate myocardial viability. (201)Tl lung uptake significantly correlated with pulmonary wedge pressure (r=0.66; P:<0.01) and with a restrictive physiology by Doppler echocardiography (P:<0.001). During a 13+/-13-month follow-up, 13 patients died and 23 patients required hospitalization as the result of worsening heart failure or nonfatal myocardial infarction (cumulative events rate 29%). Patients with events had a significantly higher (201)Tl lung/heart ratio (L/H) (P:<0.001). A L/H value >0.61 best separated patients with and without events (ROC area under curve 0.82). Event-free survival was significantly lower in patients with L/H >0.61 (P:<0. 001); L/H >0.61 (chi(2)=10.8; P:<0.001) and a restrictive filling pattern (chi(2)=3.6; P:<0.05) were independent predictors of events. The prognostic value of L/H was incremental over that obtained by clinical, echographic and Doppler data (global chi(2)=20.8). CONCLUSIONS: In patients with severe postischemic left ventricular dysfunction undergoing rest-redistribution (201)Tl imaging, an increased lung tracer uptake showed incremental prognostic value over clinical and other imaging findings, providing clinically useful risk assessment.

Adult↗
PubMed1999

High dose dipyridamole myocardial imaging: simultaneous sestamibi scintigraphy and two-dimensional echocardiography in the detection and evaluation of coronary artery disease. Italian Group of Nuclear Cardiology.

BACKGROUND: Dipyridamole stress combined with echocardiography or perfusion scintigraphy can be used to detect coronary artery disease, but head-to-head comparative data are lacking. The aim of this study was to compare the relative accuracy of high-dose dipyridamole stress imaging (up to 0.84 mg/kg over 10 min) with two-dimensional echocardiography and sestamibi perfusion scintigraphy in detecting coronary artery disease. METHODS: One-hundred and one patients with a history of chest pain and no previous myocardial infarction, were studied simultaneously using planar perfusion scintigraphy and echocardiography during a high-dose dipyridamole stress, at seven different institutions. RESULTS: During coronary angiography, 21 patients had non-significant lesions, and 80 had significant lesions (> or = 50% diameter reduction): 37 had single-, 19 double- and 24 triple-vessel disease. Sensitivity for disease detection was 78% [95% confidence interval (CI) 67-86%] for echocardiography and 79% (CI 68-87%) for scintigraphy. The specificity was 76% (CI 67-84%) for echocardiography and 90% (CI 83-95%) for scintigraphy. The inter-center variation in accuracy ranged from 50 to 100% for echocardiography (coefficient of variation 19.7%) and from 71 to 100% for scintigraphy (coefficient of variation 15%). The angiographically assessed extent and severity of coronary artery disease, evaluated using the Duke score, was correlated to the extent and severity of perfusion defects with scintigraphy (r = 0.65, P < 0.0001) and regional wall motion abnormalities by echocardiography (r = 0.57, P < 0.0001). CONCLUSIONS: Perfusion scintigraphy and echocardiography have similar accuracies for the non-invasive identification of angiographically assessed coronary artery disease during high-dose dipyridamole stress. Inter-center variability in diagnostic accuracy is higher for echocardiography than scintigraphy. Both methods allow a reasonably accurate estimation of extent and severity of disease, via a semiquantitative assessment of extent and severity of perfusion of functional defects.

Aged↗
PubMed1998

Heterogeneous fate of perfusion and contraction after anterior wall acute myocardial infarction and effects on left ventricular remodeling.

After acute myocardial infarction, patency of infarct vessel and extent of left venticular (LV) dysfunction are major determinants of ventricular remodeling. Spontaneous, delayed reperfusion in the infarct zone occurs in a sizeable number of patients well after the subacute phase. The aim of this study was to determine the relation between the occurrence of this spontaneous, delayed reperfusion and LV remodeling. In 84 patients, resting LV volumes, topography, regional function, and perfusion were quantitatively evaluated by 2-dimensional echocardiography and sestamibi tomography 5 weeks (study 1) and 7 months (study 2) after anterior Q-wave infarction. At study 2, LV end-diastolic volume increased by > 15% in 17 patients (20%, LV remodeling); they had already had at study 1 significantly larger LV volumes, more severe hypoperfusion and wall motion abnormalities, and greater regional dilation than patients with stable LV volumes. Delayed reperfusion occurred in 8 of 17 patients with and in 42 of 67 patients without LV remodeling (47% vs 63%; p=NS). At study 2, LV regional dilation and end-diastolic volumes were stable in patients with, but increased in patients without, spontaneous reperfusion (from 25+/-24% to 29+/-26% at study 2 [p<0.05] and from 65+/-14 to 68+/-18 ml/m2 [p <0.05]). At multivariate analysis, however, regional ventricular dilation at study 1 was the sole predictor of further LV remodeling. Thus, after acute myocardial infarction, spontaneous reperfusion occurring after 5 weeks plays only a minor role in influencing LV remodeling. Benefits from delayed reperfusion seem limited to patients with preserved LV volumes; patients with an enlarged left ventricle 5 weeks after acute infarction are prone to further LV remodeling, irrespective of delayed reperfusion.

Adult↗
PubMed1998

[Pulmonary uptake of thallium-201 at rest and diastolic function in patients with ischemic cardiopathy and left ventricular dysfunction].

An elevated thallium-201 lung uptake after stress is currently considered a marker of severe coronary artery involvement and related to adverse prognosis. The meaning of this scintigraphic finding on rest thallium-201 images is yet poorly investigated. We compared the thallium-201 lung uptake and the left ventricular diastolic function from mitral Doppler in 24 patients (64 +/- 10 years) with ischemic heart disease and severe left ventricular dysfunction (ejection fraction 28 +/- 10%). All patients underwent a 3-view planar rest-redistribution thallium-201 and 2D-echo studies within 6 days, while clinically stable. The amount of thallium-201 lung uptake was quantified as the ratio (L/H) between the activity in a left lung region of interest (L) and that observed in the left ventricle (H). From mitral Doppler, early (E) and late (A) filling velocities, the E/A ratio and the deceleration time of early filling (DecT) were calculated. An elevated L/H (> or = 0.54) was observed in 9 patients (37%). They showed a lower ejection fraction (20 +/- 4% vs 33 +/- 10% in patients with normal L/H; p < 0.01) and a higher wall motion score index (2.5 +/- 0.4 vs 2.1 +/- 0.4, p < 0.05). A significant inverse linear relation was observed between L/H and the left ventricular ejection fraction (r = -0.70); no significant relation was observed between L/H and left ventricular end-diastolic volumes or wall motion score index. A significant linear relation was also observed between L/H and E/A (r = 0.74; p < 0.001) as well as L/H and DecT (r = -0.61; p < 0.001); an even stronger, inverse, relation was found between L/H and A (r = -0.81; p < 0.001). An abnormal L/H identified 80% of patients with a restrictive filling pattern (specificity 93% and accuracy 88%, respectively). In conclusion, in stable patients with ischemic heart disease and ventricular dysfunction, L/H on rest thallium-201 images is closely correlated with Doppler indexes of left ventricular diastolic filling dynamic; an abnormal L/H is highly predictive of a restrictive filling pattern.

Aged↗
PubMed1997

ECG-manifest and ECG-silent dipyridamole technetium-99m sestamibi SPET perfusion defects in patients with ischaemic heart disease.

At dipyridamole myocardial scintigraphy, perfusion defects are seldom backed up by significant ECG changes. This would suggest myocardial blood flow heterogeneity, rather than true ischaemia, as the cause of the scintigraphic abnormalities. Electrocardiographic surface mapping has been documented to be more accurate than standard 12-lead ECG in the detection of provoked ischaemia. Thus, to investigate the relationship between ECG changes and perfusion abnormalities, body surface maps were recorded during dipyridamole infusion in 55 subjects (11 normals and 44 patients with ischaemic heart disease) undergoing dipyridamole technetium-99m sestamibi single-photon emission tomography (SPET). All had a normal resting ECG. The extent and severity of the sestamibi defect were quantified. New negative areas in the isointegral maps and rest-dipyridamole map differences >2 SD from normal limits were considered abnormal. After dipyridamole in normals, neither perfusion defects nor >/=1 mm ST segment depression on 12-lead ECG nor new negative areas in isointegral maps occurred. In patients, dipyridamole induced new perfusion defects in 35 (80%) but ST segment depression in only 18 (41%, P<0.001). Of the 35 patients with perfusion defects, 17 (49%, group 1) showed ST segment depression, while the other 18 (51%, group 2) did not. Abnormal body surface maps were found in 100% of group 1 and 88% of group 2 patients (NS). In group 1, the provoked hypoperfusion was of greater extent (P=0.007) and severity (P=0.01) and the onset of map abnormalities was significantly earlier (P<0. 001) than in group 2; time to map abnormalities was also significantly shorter than time to ST segment depression (P=0.01). In the 35 patients with complete scintigraphic, body map and angiographic data, the severity of reversible perfusion defect proved to be the strongest correlate of ST segment depression upon logistic regression analysis. Thus, sestamibi SPET abnormalities after dipyridamole are almost always associated with electrical changes on body surface maps, suggesting myocardial ischaemia as their cause. The much less common 12-lead ECG changes are slower to appear and reflect a more severe hypoperfusion.

Body Surface Potential Mapping↗
PubMed1997

Ischemic burden in silent and painful myocardial ischemia: a quantitative exercise sestamibi tomographic study.

OBJECTIVES: We sought to determine whether the amount of myocardial ischemic burden differs in patients with painful or silent myocardial hypoperfusion during exercise testing. BACKGROUND: Whether a lack of symptoms during ischemia reflects an alteration in pain perception or less myocardium in jeopardy remains a controversial issue. METHODS: We studied 300 consecutive patients with a well established history of ischemic heart disease and reversible hypoperfusion on exercise sestamibi tomography. Rest and stress sestamibi defects were quantitatively assessed and indexes of exercise left ventricular dilation derived. RESULTS: Painful and silent reversible ischemia was observed in 97 (32%) and 203 (68%) patients, respectively. Patients with painful ischemia had lower values for work load, exercise time and peak rate-pressure product (p < 0.01) and more frequently showed significant ST segment depression during exercise than did patients with silent ischemia (69% vs. 40%, p < 0.001). On sestamibi tomography, patients with painful ischemia had more reversible hypoperfusion than did patients with silent ischemia (mean +/- SD 16 +/- 10% vs. 11 +/- 7%, p < 0.001), despite a comparable extent of stress hypoperfusion (22 +/- 12% vs. 22 +/- 13%); they also had a higher endocardial dilation index (1.32 +/- 0.32 vs. 1.10 +/- 0.26, p < 0.001). By multivariate logistic analysis, the most powerful correlate of painful ischemia was a history of effort angina; the extent of reversible perfusion defect was the sole independent scintigraphic correlate of painful ischemia. CONCLUSIONS: To our knowledge, this is the largest study comparing the degree of hypoperfusion and the presence of symptoms during exercise stress testing in a consecutive cohort of patients with ischemic heart disease and reversible hypoperfusion. The results suggest that the ischemic burden is greater in painful than in silent ischemia.

Adult↗
PubMed1997

Rest-redistribution thallium-201 and rest technetium-99m-sestamibi SPECT in patients with stable coronary artery disease and ventricular dysfunction.

UNLABELLED: Resting sestamibi uptake was compared with 201Tl rest-redistribution uptake in 48 patients with ischemic heart disease and regional ventricular asynergies. METHODS: In 48 patients, rest/4-hr redistribution 201Tl and resting sestamibi tomography were closely performed on separate days. Segmental tracer uptake was quantified. Wall motion in corresponding segments was also assessed by two-dimensional echocardiography in 17 patients. RESULTS: Quantitative analysis indicates that the uptake of the two tracers was comparable in normal segments as well as in segments with fixed 201Tl defects. In contrast, in segments with reversible 201Tl defects, sestamibi uptake was significantly lower than redistribution 201Tl uptake. CONCLUSION: In patients with chronic ischemic heart disease and regional asynergies, quantified sestamibi activity parallels 201Tl redistribution activity in normal segments and in those with fixed 201Tl defects. In segments showing reversible 201Tl defects, whether or not dysfunctioning, sestamibi uptake is significantly lower than 201Tl redistribution.

Aged↗
PubMed1996

[Exertion-induced myocardial ischemia has little influence on ventricular remodeling in post-infarction patients with preserved systolic function].

BACKGROUND: The effects of acute and recurrent ischemia on ventricular function are well documented. However, the role of residual exertional ischemia in the remodelling process after infarction has not yet been established. In this study, we investigated whether exercise-induced myocardial ischemia influences left ventricular remodelling in patients with recent myocardial infarction and preserved left ventricular function and volumes. METHODS: Sixty-four patients with a first anterior Q wave myocardial infarction were studied at 5 weeks by rest echocardiography and exercise scintigraphy; the echocardiographic examination at rest was repeated 6 months later. Based on the presence and extent of reversible perfusion defects on exercise scintigraphy, patients were classified as having no exertional ischemia (group 1, n = 13 [20%]), mild to moderate ischemia (group 2, n = 32 [50%]) and severe exertional ischemia (group 3, n = 19 [30%]). RESULTS: At 5 weeks after infarction left ventricular volumes, ejection fraction, percent wall motion abnormalities and regional dilatation were similar in the three groups. After 6 months, end-diastolic and end-systolic volumes and regional dilatation did not change in patients in all groups, while ejection fraction and percent wall motion abnormalities showed a slight but significant (p < 0.01) improvement in all groups. CONCLUSIONS: Exercise-induced myocardial ischemia, either mild or severe, does not affect ventricular remodelling and function after myocardial infarction in patients with preserved ejection fraction.

Adult↗
PubMed1996

Thallium-201 reverse redistribution at reinjection imaging correlated with coronary lesion, wall motion abnormality and tissue viability.

UNLABELLED: Previous studies based on standard stress-redistribution 201TI scintigraphy provided conflicting results about the clinical significance 201Tl reverse redistribution. Recent observations indicate that the majority of these defects normalize following reinjection reflecting viable myocardium. METHODS: In this study, the meaning of reverse redistribution occurring at reinjection imaging, its relation to standard 4-hr redistribution, coronary lesion, abnormal wall motion and tissue viability were assessed. A region with normal activity in the stress image was considered as having reverse redistribution if 201Tl activity at reinjection imaging was definitely abnormal with a decrease in relative tracer uptake >15% of the peak. From a series of 270 patients, 29 showed reverse redistribution. Of these 29 patients, 27 had evidence of previous myocardial infarction. Coronary lesions were detected in all but 1 patient. Average ejection fraction was 0.38 +/- 0.11. RESULTS: On a segmental basis, 50/377 regions showed the pattern of reverse redistribution. A significant coronary lesion (> or = 50%) was found in 78% of these regions; occlusion rate was 50%, and collateral circulation was found in 35% of occluded vessels. Hypokinesis or akinesis was present in 72% of segments. Tissue viability, defined as an uptake >55% of the peak, was found in 44% of these segments. The 50 segments showing reverse redistribution were divided into two groups according to an abnormal uptake also at 4-hr redistribution (group 1, 25 segments) or appearing only following reinjection (group 2,25 segments). Despite segments of group 1 showing a higher degree of coronary stenosis (80 +/- 32 versus 59 +/- 43%, p < 0.01), a similar rate of coronary occlusion, ventricular dysfunction and maintained viability was found in the two groups. CONCLUSION: Reverse redistribution in chronic coronary artery disease is frequently associated with significant coronary lesion, collateral-dependent dysfunctioning myocardium and preserved tissue viability. The occurrence of reverse redistribution following reinjection expands the indication for viability imaging to all patients with known coronary artery disease and regional wall motion abnormalities who undergo diagnostic and prognostic 201TI scintigraphy.

Coronary Angiography↗